The invention relates to a magnetic levitation railway and to a magnetic levitation vehicle therefor.
Known magnetic levitation railways of this type are driven, for example, by long-stator linear motors which are provided with three-phase alternate current windings laid in a long stator alongside the guideway. The excitation field of the linear motors is supplied by carrier magnets simultaneously acting as excitation magnets and arranged in the vehicle (DE 39 19 058 C2). Apart from driving, the linear motors can also be utilized for braking the vehicles. For this purpose, it is merely necessary to feed an electric current with a sign opposite to the usual operation during travel into the three-phase alternate current windings of the relevant long stator.
Since there does not exist any possibility of braking when e.g. individual magnets or all carrier and excitation magnets fail to work, magnetic levitation vehicles destined to run at high speed are additionally equipped with a so-called “safe” brake, which for example may be a compressed-air brake (DE 30 04 705 C2). As magnetic levitation vehicles are in any case provided with carrier and guide magnets, it lends itself to utilize an eddy-current brake also comprised of magnet arrangements to serve as a safe brake, which is true for a magnetic levitation railway of the species designated hereinabove (e.g. ZEVrail Glasers Annual Reports, Special Edition Transrapid, October 2003, Page 63) At pre-selected positions, such an eddy-current brake is provided with brake magnets which co operate with electrically conductive, laterally arranged guiding and/or reaction rails, are mounted at the guideway and generate eddy currents therein acting as a brake. A disadvantage is that the normal forces additionally generated by the brake magnets vertically to the reaction rails increase as the speed of the vehicle decreases, particularly if the eddy-current brakes are regulated to a constant brake force and therefore call for ever greater currents to maintain the desired brake forces, the more the vehicle speed decreases. Consequently, the forces acting upon the reaction rails increase so much that they exceed admissible, critical values and may thus cause damage to the mechanical anchoring of the reaction rails. Up to now it has only been possible to remedy this situation by reinforcing the mechanical structure of the guideway accordingly.